Abstract The aim of this randomized controlled trial (RCT) competing continuation is to evaluate the long-term population impact and mechanisms of Family Connects (FC), brief universal nurse home-visiting program designed to prevent child maltreatment in an entire community population. Between July 1, 2009, and December 31, 2010, every infant born in Durham on an even birth date (n=2,329 births) was assigned to receive the FC Program, and all infants born on an odd birth date (n=2,450 births) received services-as-usual. Evaluation of implementation indicated high penetration (80.0% of all births consented to participate), high fidelity to the model (84% adherence), and high reliability of scoring risk factors (?=0.69). Intent-to-treat impact evaluation with a representative random sample from intervention (n=269) and control (n=280) birth dates indicated that families randomly assigned to FC accessed more community resources and exhibited less anxiety and better parenting behavior. Hospital records indicated FC families had fewer emergency medical care visits and overnights in the hospital through age 24 months, and child protective service records indicated 39% lower rates of investigations for child maltreatment through age 60 months. The proposed study will continue to follow families participating in the existing impact evaluation study from child ages 9 to 12 years. Administrative records will evaluate impact of random assignment to FC on child maltreatment cases, emergency room maltreatment-related injuries, and education outcomes. In-home and telephone interviews with parents and children, as well as blinded observations, will assess parental functioning and child well- being. Teacher surveys will assess child academic performance and social-emotional adjustment. Data analyses will test five hypotheses: 1) Random assignment to the FC program (that is, being born on an even birth date) will be associated with lower rates of child maltreatment and emergency department utilization, better academic outcomes, better parental functioning, and better child well-being than assignment as control; 2) FC will produce a positive benefit-cost ratio, as measured by outcomes in health, mental health, social, and education services received; 3) Intervention effect sizes will be larger for higher-risk groups; 4) Community resource use and enhanced family functioning will mediate the positive impact of FC on outcomes; and 5) Developmental processes in dysfunctional parenting and child behavior among the control group will conform to the model guiding the program. This proposal offers an urgent, time-constrained opportunity to evaluate the long-term population impact and mechanisms of this innovative universal home-visiting program. The project will contribute to public health by evaluating the long-term impact and mechanisms of a program that aims to lower the population rate of child maltreatment in a cost-effective way and by testing models of the development of maltreatment, dysfunctional parenting, and child behavior and well-being.